Structural element

ABSTRACT

Structural element characterized by its rigidity and very light weight per unit but simpler and readily formed at every scale, which is constructed using a first piece or preform which comprises a plurality of projections and a second piece which can be a second preform, a sheet or a mesh, wherein both pieces are fixed by means of the plurality of tips of the plurality of projections fixing them by any fixing means appropriate to the materials used and to the application of the structural element.

BACKGROUND OF THE INVENTION

This invention relates in general to the structural support for lightweight panels. More specifically it relates to structural elements whichcomprise preforms of any moldable, deformable or laminar material likepaper, cardboard, plastics, reinforced resins, metals, alloys, compoundmaterials, agglomerates, asbestos, gypsum, ceramic, glass or any othersimilar material, any of which is formed in such a way as to have a veryhigh structural resistance to compression and to flexure, maintaining alow weight and having a configuration which allows to comprise supportpoints to which other preforms or sheets of any material can be affixedto construct the structural elements.

The technical aspects and advantages of structural sandwich panels arewell known, because they have been used for structures that require avery high resistance and a very low structural weight. The so calledhoneycomb sandwich panels are well known among this type of panels. Inthis type of structures, the panel is constructed by means of strips ofthe material used that are fixed together at some points in such a waythat the hexagonal honeycomb is established, in which such honeycombsextend perpendicularly to the sheet or sheets with which the sandwich isconstructed. The strips that form the honeycomb extend longitudinally ina cross sectional way to the sheet or sheets that form the sandwich.This means that the strips forming the honeycomb extend perpendicularlyto the sheets that form the sandwich panel. Other configurationsdifferent to hexagonal can be used like triangular, pentagonal, etc.

Different materials can also be used for the construction of sandwichpanels, both for the core as well as for the sheets that form the wallsof the sandwich. Such materials can be for example, paper, cardboard,plastic, metal and composite materials. The basis of the sandwich panelsrest in keeping a core that work as a perpendicular structure supportfor the panel, while other configurations adopted throughout the time,allow to distribute the effort applied all over the panel in a more orless homogenous manner, which allow to decrease up to ten times theweight of the structural element in comparison with traditionalstructural elements formerly used, keeping under the same conditions theunder load support capacity. This type of structures have had hugeadvantages by supporting the same loads at a fraction of the weight andcost of prior structural elements.

Different methods to build sandwich panels by diverse techniques havebeen discussed. A notable example could be found in U.S. Pat. No.5,028,474 dated Jul. 2, 1991, granted to Ronald M. Czaplicki entitledCellular Core Structure providing Gridlike Bearing Surfaces on OpposingParallel Planes of the Formed Core.

Among the inventions made to give structural cores to sandwich panels isU.S. Pat. No. 3,865,679 dated Feb. 11, 1975, granted to Jesse R. Hale,entitled Sandwich Panel having Cellular Core Structure with ReinforcingElements, which teaches a core structure that has nodes, shown inessentially circular manner, that project in opposed directions form amid plane with apices of said nodes abutted against the face sheets ofthe panel, comprising first reinforcing bar means running along to thesides of a first row of said nodes, wherein said bar means are bonded tothe sides of said nodes of said center and to the surface of one of theface sheets of the panel and a second reinforcing bar means that runalong of a second row of said nodes, wherein said second reinforcing barmeans are bonded to the surface of one of the face sheets. This patentcomprises as improvement the addition of reinforcing bars that arebonded to the face sheets of the nodes along two different rows of nodesand are bonded by the ends to the face sheets of the sandwich panel. Itis evident that the structure used in this invention, requires anadditional reinforcement to support the stress that will be applied tothe panel and will not be discussed in more detail.

In U.S. Pat. No. 5,028,474 above described, in a three dimensionalstructure that comprises ridges and essentially lineal valleys whichestablish spaced rows of adjacent inclined rectangular shaped facetsconnected by intermediate rows of adjoining parallelogram-shaped facets,wherein said structure is made by folding of a continuous unbroken sheetmaterial, wherein said laminate material has a superficial area and saidsuperficial area is filled of a repetitive path of cellular units. Thecentral structure provides support surfaces of the grid type in twosupport plan parallel opposed to which the plates or sheets can be fixedas faces to form the panel in the form of a sandwich.

From the prior description and the accompanying drawings to the patentof Czaplicki, it should be appreciated the problem to establish theactual way in which the plate or sheet is folded, which finallyconstitutes a three dimensional figure but with different geometricfigures. This relative obstacle to fold the plate or sheet does notallow to adequately appreciate the value of this invention. U.S. Pat.No. 5,182,158 dated Jan. 26, 1993, granted to Barnarr C. Shaeffer titledLightweight Sandwich Panel, wherein in a sandwich panel which comprisesexternal layers which has projections bonded to the other externallayer, wherein the projections have relatively flat areas in theiredges, in the edges freed to provide enlarged areas for bonding, whereinthe flat areas are bonded chemically to the other external layer, thecore layer is a plastic sheet and the projections are formed from thesheet and the projections by area would vary in density to providedifferent resistances to the deflection in various parts of the panel,wherein one of the external layers is transparent and the core layer isdark to absorb the sun's ray and is open to the passage of air throughit. It can be clearly appreciated from the prior description that thepatent to Schaeffer has been designed for its application to aviation ingeneral, wherein it can be appreciated in FIGS. 2 to 4 that differentcross section sheets are used also bonded to form a honeycomb. In FIG. 5it could be appreciated a structure with steep projections. The instantinvention differs from Shaeffer as will be herein further described.From the foregoing it could be appreciated that these structures in theform of sandwich are formed by three or more pieces, which makes verycomplex its construction, structure or use. Diverse geometrical shapepanels with thin metallic sheets have also widely been described, likein U.S. Pat. Nos. 3,209507; 3,622,430; 3,834,487 and 3,938,963, or thereare also inclusive those patents which illustrate systems of themulticonical type as U.S. Pat. Nos. 4,672,780 and 4,794,742, but in noneof these cases, these patents have the advantages of the instantinvention.

SUMMARY OF INVENTION

According to the foregoing, it is an object of the present invention toprovide a structural element with a simpler design and improvedproperties respect to the prior art. It is another object of the presentinvention to provide a structural element with outstanding structuralfeatures and of relatively easy and very economic construction.

It is still another object of the present invention, to provide astructural element with a three dimensional structure, which comprisesat least a deformable or moldable continuous material preform along allof which a plurality of projections are formed in successive orsimultaneous steps in such a way that the projections can be generallybut not necessarily symmetrical.

Still a further object of the invention, is to provide a structuralelement that is susceptible of being lightened by withdrawing all theunnecessary material to make the functions of support and structuralreinforcement given by the structural element and besides increasing itspossibilities of application. It is still an object of the invention, toprovide a structural element which is susceptible of being manufacturedby units, lots or continuously, comprising a first piece of a materialand a second piece of the same or different material.

The present invention comprises a structural element starting basicallywith two pieces made or formed with a laminate material, projections aremade together or very close to each other to one or both pieces in aregular or irregular manner. These projections can be pyramids, orprisms of square, rectangular, triangular or hexagonal base, etc.,complete or truncated and with right or rounded edges or of any othertype, inclusive cones or ovoids, etc. Whenever at least a preform isjoined together to another piece which may be a smooth surface, anotherpreform or any combination, they form a structural element. Formedpanels are flexible and can be given any wanted shape to be flat orcurved, but upon fixing the tips of the projections of the first piecefixed to the second piece which can have a smooth surface, otherpreform, another piece that can be prepared to facilitate the fixing, ora mesh, a three dimensional structure is built that maintains its givenshape with great rigidity and very low weight, which structure besidesthe thickness of the formed panel give to such panel extraordinaryresistance to flexion and to perpendicular compression. Any material canbe used to manufacture these structures being the most convenient thatwhich allow a continuous massive production like: metals, alloys,plastics, rubber, paper, cardboard, composite or agglomerated materials,reinforced resins, concrete, gypsum, ceramic materials, asbestos, glassand others. The two pieces that form the panel can be manufactured withthe same or different material. Any reinforcement can be added withinthe structure to increase the resistance and if convenient anynonconductor or filling material and externally faces can be put whichcomplete the finishing and improve the appearance, giving as a result asandwich panel. As in most of the cases it will be convenient toprebuild the structural elements for using them in another place, fixingmeans can be added to the edges to fix the panels to each other and tofix the panels to other portions of a construction, building or finalproduct. The structure can have any thickness, though the most commonwill be between 5 and 150 millimeter, nonetheless it is possible tobuild smaller or bigger panels to an extent in which the projectionscould be arranged in little groups or alone to be fixed one to the otherand at the same time to the other portion of the structure. This type ofstructure can be lightened by withdrawing the material of the sides ofthe projections and or the faces located between the joining points ofthe second piece achieving simultaneously a permeable structural elementthat serves as a support to other materials as would be prebuiltelements of construction. It is also possible to use a plurality ofprojections of different shape and size as a preparation for bendingbefore fixing, as it would be for the manufacture of beams or otherstructural elements. Equally it is also possible to prepare thestructural element to ease the joining of the two pieces or to add otherfeatures, like adding some projections to make it antislipping. Theflexibility of the instant invention allows a prior manufacture of thepreform to build the panels thereafter when the application takes place.Depending on the materials used the structural elements also can be usedas buffer elements, for isolation, decoration, stage scenes, reflectiondiffusion and lots more. It should be appreciated that this type ofstructural elements is easier to manufacture than normal sandwich panelslowering the cost which allows to use its advantages of light weight andrigidity at an affordable price.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features and advantages of the instant invention should bereadily apparent for those skilled in the art arising from the teachingsof the detailed description herein and the accompanying drawings, but itshould be understood that the instant invention can be embodied indifferent ways and that the embodiments herein described are shown forillustration purposes only, but that they are not restrictive asreferred to the scope of the invention wherein:

FIG. 1 is a perspective view of the preform and sheet type panel,

FIG. 2 is a cross cut view along AA' axis of the panel of FIG. 1,

FIG. 3 is a view of a formed panel,

FIG. 4 is a perspective view of an embodiment of the present inventionwherein a portion of the material of the walls of the projections and ofthe spaces between the joining points is withdrawn to lighten the panelas to form a panel with modified properties,

FIG. 5 is a perspective view of another embodiment of the inventionwherein a panel with two preforms is shown, both preforms are lightenedand fixed by the tips and have recesses in their solid faces,

FIG. 6 is a perspective view of a fourth embodiment of the inventionwherein a panel is formed with two lightened preforms, and which arejoined fixing the tips of the projections of one preform with thebottoms of the projections of the other preform,

FIG. 7 is a perspective view of a panel formed with a sheet withrecesses which are used to fix the preform, wherein said recesses arealso used as anti slipping projections, and

FIG. 8 is a cross cut view along BB' axis wherein the projection tipsshown can be seen fixing to the sheet in the recesses formed in theplate.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, numeral 10 generally designates a first pieceor preform which can be fixed to a second piece or sheet 12, which actsas a joining surface of the tips of the geometric shapes used in thefirst piece or preform 10 to fix them in place. Once the preform 10 andthe second piece or sheet 12 are fixed, they form the structural element14, which can be a part of a plurality of articles which can be appliedto the building industry. During the forming process of preform 10, therelatively flat bottoms of every geometric shape formed and theresulting material between them form a face of the structural elementswhich can be added another laminar piece which depends on the desiredfinishing for the particular application.

In FIG. 2, a cross cut along AA' axis of panel 14 can be seen, whereinthe geometric shapes of preform 10 can be clearly seen, sheet 12 fixedto preform 10 by tips 20 and how it is firmly supported by projections16 and how bottoms 18 of projections 16 establish a relatively flatcontinuous surface, wherein it can be appreciated that another sheet 12is unnecessary on the opposite side to that which sheet 12 is fixed topreform 10, because the particular system formed by bottoms 18 which areformed longitudinally and transversely to preform 10, give enoughrigidity to structural element 14 so any additional support isunnecessary.

In FIG. 3, a panel 22 is shown to illustrate the different shapes thatthis type of panel can have.

In FIG. 4, it is shown a hollowed preform 24 to which a portion of thematerial of sides 26 of projections 16 and material between the joiningpoints of sheet 28 has been withdrawn. This embodiment allows to lightenthe structure to apply it to such articles or building applications thatrequire a strict control of the total weight while maintaining therigidity of the whole structure, or when it is desired to have apermeable panel which allows the passage of other objects or fillingmaterials.

FIG. 5 shows another embodiment of the invention wherein two hollowedpreforms are fixed by their tips as to form a panel by a first piece orpreform 24 and a second preform 24', which form panel 30. This type ofpanel can also be formed with other shapes and sizes to maintain anadequate ratio to allow the tips of both preforms 24, and 24' toregister in place to establish the joining points to fix the preform andform the panel even though such panel has a different to flat shape.

FIG. 6 shows other embodiment of the invention, wherein a first hollowedpreform 24 is fixed to a second hollowed preform 24' as to fix the tipsof first preform 24 to the recesses in the inner portion betweenprojections 28' of second preform 24' while fixing the tips of secondpreform 24' to the recesses in the inner portion between projections 28of first preform 24 to form panel 32. This configuration allows to fixto some points the sides of projections 28 and 28' of both preform togive an increased resistance to the structure. In this figure hollowedpreforms were used that were lightened by withdrawing a portion ofmaterial to the sides of the projections, but in the case in whichpreforms were complete continuous surfaces they could establish closedspaces between every four projections two of every preform, whereinfaces can be applied to both sides of the panel giving a plurality ofclosed spaces adjacent one to the other with superb isolating andbuffering features besides its properties of light weight, resistanceand ease of manufacture derived from the main principle of theinvention.

FIG. 7 shows a view of another embodiment of the invention, wherein afirst piece or preform 10 is fixed to a second piece 34, which hasrecesses 36 comprised on the inner face of second piece 34, whichcomprise a plurality of projections 38 in the external face of saidsecond piece 34, once fixed the first piece 10 to second piece 34 theyform panel 40, which has special characteristics because of theprojections which can give the surface an antislipping property when theconstruction element is used for floors or the like.

FIG. 8, shows a cross cut along BB' axis of panel 40 in FIG. 7, whereinrecesses 36 can be readily appreciated comprised in the inner face ofsecond piece 34, and the way in which said recesses are used to receiveinside them the tips of projections of first piece or preform 10 to fixboth pieces and to form panel 40. Projections 38 can also be appreciatedas established on the exterior face of second piece 34 and which give tothe panel improved properties over the panels of prior art.

From the foregoing description it should be appreciated that multiplechanges and modifications can be made to both first and second piecesand to the whole structural element once it is formed as to make aplurality of structural elements adapted to different uses and based ontheir structural rigidity, light weight and also on their structuralshape which allows to make precise bendings which also can be used fordecoration. It should be understood that the foregoing description andthe different embodiments of the invention are used herein forillustration purposes but are not limitative and that this modificationsare within the scope and spirit of the invention.

What I claim is:
 1. Structural element which comprises a first piece andat least a second piece wherein at least said first piece comprises aplurality of projections which establish a preform and said second piececomprises a relatively smooth surface and receives said first piece,wherein said projections of said first piece are fixed to said secondpiece which upon fixing establish a very rigid, resistant to flexure andlight weight tridimensional structure, each of said projections of saidfirst piece comprising a base, each of said projections of said firstpiece being selected from the group consisting of:a. a solid projection;and b. a projection including at least one aperture through at least oneof projecting side walls of said projection, all of said bases forming asubstantially continuous surface, said first piece and at least saidsecond piece comprising an interior component of said structural elementof substantially the same rigidity as at least one layer of saidstructural element exterior to said interior component, said first pieceand at least said second piece comprising said at least one layer ofsaid structural element, said at least one layer of said structuralelement being substantially rigid.
 2. Structural element according toclaim 1, wherein said projections comprise different geometric shapesand sizes.
 3. Structural element according to claim 1, wherein saidprojections of said first piece are fixed by means of a plurality ofrecesses comprised on an inner face of said second piece.
 4. Structuralelement according to claim 1, wherein both pieces are similar andwherein the projections of said first piece are fixed to the projectionsof said second piece.
 5. Structural element according to claims 1,wherein both pieces are similar and the projections of said first pieceare fixed to recesses between the projections of the second piece. 6.Structural element according to claim 1, wherein said second piece is amesh.
 7. Structural element according to claim 1, wherein said first orsecond pieces are hollowed to lighten the element and to allow thepassage of other objects or materials.
 8. Structural element accordingto claim 1, wherein both first and second pieces are hollowed to lightenthe element and to allow the passage of other objects or materials. 9.Structural element according to claim 1, wherein said element hasstructural projections with different shapes and sizes to have a finalshape by means of bending or curving before fixing.
 10. Structuralelement according to claim 1, wherein said element is made by means ofbending and curving said piece and fixing its projections on itself. 11.Structural element according to claim 1, wherein said pieces of saidelement comprise a deformable, moldable or laminar material. 12.Structural element according to claim 1, wherein said element comprisespieces made of the same material.
 13. Structural element according toclaim 1, wherein said element comprises pieces made of differentmaterials.
 14. Structural element according to claim 1, wherein at leastone of the pieces comprise a face and finishing.
 15. Structural elementaccording to claim 1, wherein said element comprises reinforcements. 16.Structural element according to claim 1, wherein a filling material isadded to the structural element.
 17. Structural element according toclaim 1, wherein at least one of the pieces is adapted for fixedattachment to at least another one of the pieces or installation in saidstructural element.
 18. Structural element according to claim 1, whereinat least one of the pieces comprises means for fixedly attaching said atleast one of the pieces to at least another one of the pieces. 19.Structural element according to claim 1, wherein said element furthercomprises at least one additional piece, each of said at least oneadditional piece having at least one of the following characteristics:a.having projections similar to said first piece; and b. being fixedlyattached to projections of another piece, said fixed attachment beingsimilar to the fixation of said second piece.
 20. Structural elementaccording to claim 1, wherein said plurality of projections comprisedifferent geometric shapes and sizes and at least one of said firstpiece and said second piece are hollowed and have a plurality of openapertures through at least one wall of said at least one of said firstpiece and said second piece to lighten the element and to allow thepassage of other objects or materials.